Mod10 - Genetic Engineering

Question 1

What do restriction endonucleases do?

Answer 1

Cut DNA at palindromic sequences

Question 2

What is phosphatase used for in genetic engineering?

Answer 2

The ends of the vector plasmid are treated with phosphatase to prevent recircularisation

Question 3

Which enzyme is used to join the cut DNA fragment and the vector plasmid together?

Answer 3

DNA Ligase

Question 4

What is the difference between a genomic library and a cDNA library?

Answer 4

A genomic library includes all genes, including introns, promoters, enhancers and intergenic DNA
A cDNA library only includes expressed genes (mRNA) - i.e. only exons and UTRs

Question 5

What enzyme is used to synthesise cDNA from mRNA?

Answer 5

Reverse Transcriptase

Question 6

What are the advantages and disadvantages of using bacterial and animal cells as host systems?

Answer 6

Bacteria: Cheap, Fast-Growing, Stable BUT proteins may be insoluble/denatured and no post-transcriptional modification

Animals: Proteins are soluble and properly folded, can do post-transcriptional modification BUT expensive and unstable